Describes an extremely large amount, scale, or degree, often of money, wealth, data, or effort. Used as a な-adjective or adverbial noun.
The project required an enormous amount of money.
彼は莫大な富を築いた。
He amassed a vast fortune.
malva nut (Scaphium affine)
Rare botanical term for the malva nut tree or its seed. Not commonly encountered outside specialized contexts.
莫大は東南アジア原産の植物で、種子が漢方薬に使われる。
The malva nut is a plant native to Southeast Asia, and its seeds are used in traditional Chinese medicine.
He left a vast fortune to his son.
The company went bankrupt while carrying an enormous debt.
Building a new factory requires enormous costs.
He reaped enormous profits from that investment.
We spent a huge amount of time on that project.
莫大 emphasizes a huge quantity or sum (莫大な費用), whereas 甚大 emphasizes the severity of damage or influence rather than sheer amount.
莫大 describes an enormous amount, especially of money or effort, whereas 広大 describes vast spatial or conceptual extent.